This invention relates to a method for the production of hydrocarbon materials such as oil and natural gas by the recovery of such hydrocarbon materials from subterranean oil bearing reservoirs.
When a well is drilled into a geologic formation by the conventional procedure of making hole therethrough employing a fluid which is circulated down the hole and back up to ground level, delays and additional costs are sometimes experienced because the wellbore penetrates or makes communication with a void, such as a cavity or passageways in the formation. Such occurrence generally results in a situation known as lost circulation. The term is based upon the accompanying loss of drilling fluid from the wellbore into the void to such extent that a loss of fluid impedes progess, requires the use of large amounts of emplacement fluid, and sometimes is so pronounced that the drill becomes stuck in the hole which results in down time and unscheduled expense.
Lost circulation, obviously, is a condition to be prevented or at least corrected when it exists, as expeditiously as possible. Many different approaches to solving the problem of lost circulation have been made. Some success has been derived by emplacing one or more of a variety of materials into the void or at least into the opening leading thereto. Among such materials are shredded or fragmented scrap articles including automobile tires, burlap and other fabrics, and particularly rubberized fabrics, paper, cellulosic materials, and sometimes such mineral materials as hydraulic cements, glass, and sand which are carried in an aqueous slurry, often in admixture with some of the scrap materials set forth above. Unfortunately, the success of such various blends of loss circulation materials is provided on a trial and error basis. In the more serious cases, lost circulation has continued to plague the drilling of each well being drilled in those types of formation where such voids occur frequently.
In view of the deficiencies of the prior art, it would be highly desirable to provide an effective and efficient method of sealing fractures, fissures or cavernous openings encountered during the course of drilling a well in order that there be a relatively good circulation of drilling fluid.